To compare the efficacy (in terms of patients with clear or minimal disease) of 8 weeks treatment with combination (calcipotriene plus betamethasone dipropionate) gel with that of the gel vehicle in scalp psoriasis.

To compare the safety of 8 weeks treatment with combination gel with that of the gel vehicle in scalp psoriasis.

To evaluate the efficacy and safety of 4 weeks treatment with combination ointment in psoriasis vulgaris of trunk/limbs.

Subjects With 'Controlled Disease' ('Clear'/'Almost Clear' for Subjects w. at Least Moderate Disease at Baseline, 'Clear' for Subjects With Mild Disease at Baseline) According to the Investigator's Global Assessment (IGA) on the Trunk and Limbs at Week 4.

Change from baseline to end of treatment in Total Clinical Score (TCS) of clinical symptoms (sum of erythema, scaling and infiltration).

Clinical criteria: - Change from baseline in single clinical symptom score: erythema, scaling, infiltration at end of treatment and individual visits, - Change from baseline in Total Clinical Score (TCS) at individual visits.

Ultrasonography: Change from baseline to end of treatment in lesion thickness (total and echo-poor band) measured by ultrasound.

NIR spectroscopy: Change from baseline to Day 15 and end of treatment in the ratio between the peaks at 6900 cm-1 and at 5200 cm-1, the width of the peak at 6900 cm-1 and the calculated severity score

The proportions of patients who experience adverse drug reactions and the proportion of patients who experience adverse events of concern associated with long-term topical corticosteroid use on the scalp during the study

Percentage of post-baseline satisfactorily controlled assessments according to the Investigators' Global Assessment of disease severity during the study

Subjects With 'Controlled Disease' ('Clear'/'Almost Clear' for Subjects w. at Least Moderate Disease at Baseline, 'Clear' for Subjects With Mild Disease at Baseline) According to the Investigator's Global Assessment (IGA) on the Trunk and Limbs at Week 4.

Demonstrate that at least one concentration of topical E6201 gel has superior efficacy compared with vehicle on the reduction of psoriatic infiltrate thickness during 12 days of treatment in subjects with psoriasis vulgaris

Evaluate the safety and tolerability of six topical concentrations of E6201 gel as measured by rates of adverse events, and relative to vehicle

The amount of each of the 2 active ingredients, calcipotriol and betamethasone dipropionate, in the stratum corneum obtained by means of tape stripping after application of LEO 90100 foam and Dovobet® ointment.

Difference in change from baseline in psoriatic infiltrate measured by ultrasound at Days 8, 15, 22, 29 and 43 between CRx-197, nortriptyline, active comparator as well as vehicle of CRx-197 and untreated test field(s)

Differences in change from baseline in erythema measured by chromametry at Days 8, 15, 22, 29 and 43 between CRx-197, nortriptyline, active comparator, vehicle of CRx-197, untreated test field(s) and normal skin